Paper cutting machine



g- 26, 1952 F. D. MOLAUGHLIN PAPER CUTTING MACHINE 2 SHEETSw-ShEET 1 Filed Dec. 13, 1949 3nventor Gttomeg Aug. 26, 1952 F. D. MCLAUGHLIN PAPER CUTTING MACHINE 2 SHEETSSHEET 2 Filed Dec. 13, 1949 i 1' L. J 1

Enventor w m 4 M W m 5 F W F Gttornegs Patented Aug. 26, 1952 JumrEo srATEs PATENT orrlce Frederick n. McLaughlin, Shaker Heights Ohio, assignor to The Chandler & Price Company,

, Cleveland, Ohio, a corporation of Ohio 'applieationllecember 13, 1949, Serial No. 132,758

' This invention relates as indicated to paper cutting machines and, more particularly, to novel knife control means therefor.

The usual paper cutting machine comprises a'table provided with back and side gauges for properly positioning a stack of sheets thereon, a binder clamp operative firmly to clamp such stack upon the table, and a generally vertically reciprocable knife adapted to be brought down upon the stack thus clamped to trim the latter. The present invention is concerned only with means for effecting proper control of the knife bar andknife during making of the out. For. a detailed description and explanation of certain preferred mechanism for operating the binder clamp and knife, reference may be had to the following co-pending applications of William C. Rupp, namely, application Serial No. 60,341, Paper Cutting Machine, filed November 16, 1948; application Serial No. r 112,659, Brake Mechanism for Paper Cutting Machines and the Like, filed August 27, 1949; and application Serial No. 123,865, Knife Control for Paper Cutting Machine, filed October 27, 1949. f j

In substantially all paper cutting machines where the table is at all wide, there is a definite tendency on the part of the knife and knife bar to bend or bow rearwardly in their center portions due to the bevel of the knife when such knife is making the cut. This tendency is less when cutting enameled stock but the deflection is sometimes as much as .015 inch when cutting sulphide bond with a 37-inch knife. This deflection could, of course, be reduced by employing a still more massive knife bar but such modification is undesirable for several reasons such as increase in material costs, an increase in the power necessary for rapid reciprocation of the knife bar and knife and obstruction of the lighting means which it has been found to be very desirable to provide in the upper housing of'the machine to illuminate the stack where engaged by the binder clamp. In consequence, it has been usual merely toignore such deflection and resultant inaccuracy of the out since the same is' not sufficient to be material for manypurposes. In a number of instances, however, extreme accuracy is desired and machines now on the market are not found satisfactory." It is accordingly a, primary object, of my invention to provide apaper cuttingtmachine including means insuring the obtaining of an extremely accurate out. 1

Another object -,is to provide knife control means effective to prevent rearward bowing or deflection of the knife bar and knife during the out.

Still another object is to provide means supporting the knife and knife bar against rearward deflection whereby the employment of a relatively light knife bar is made feasible, thus facilitating rapid reciprocation of the same and avoiding interference with illumination of the stack by lighting means within the upper housing of the machine.

Other objects of my invention will appearas the description proceeds;

To the accomplishment of the foregoing and related ends, said invention then comprisesthe features hereinafter fully described and partic ularly" pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicativahowever, of but a few of the various ways in which'the principle of the invention may be employed In saidannexed drawing: I I

Fig. 1 is a front elevational perspective view of a typical paper cutting machine embodying my invention;

Fig. 2 isa front elevational view of a modified binder clamp which-I employ -in-association with the knife bar of my machine; I e v,

Fig. 3 is a top plan view of such binder clamp;

Fig. 4 is a vertical sectional view taken along the line 4-4 on Fig. 2; and v 1 Fig. 5 is a vertical sectional view transversely through such binder clamp and knife bar showing the manner in which the same cooperate to achieve the objectives, of my invention.

. Referring now more specifically to such drawing and especially Fig. 1 thereof, the paper cutting machine thereillustrated is of generally conventional construction comprising a base frame I carrying a bedor table 2 upon which'a stack of sheets may be positioned to be cut. A'back gauge 3may' be adjusted forwardly or rearwardly of table 2 by means of hand wheel 4, the position of such gauge being indicated by atraveling steel tape in window 5 asdescribed in Reichart et a1. Patent No. 22035417. A knife bar 6 carrying. knife I is mounted for generally vertical reciprocation in upper frame 8, a wooden knife stick 9. being. inset in the upper surface of the table to avoid possible damage'to the knife.

The kn ife bar 6 and knife! are adapted'thus to be 'recipro'cated by means of a connecting rod. ill, crank II, and crankshaft, I2 driven through a clutch'from a flywheel driven .byan electric motor (not shown): Such'clutch Back gauge 3 may be shifted back and forth as desired by means of hand wheel 4 and locked in adjusted position by locking lever I4.

Referring now also to Figs; 2-5-inclusive,v a

binder clamp I5 is mounted forverticalreciprocation directly behind knife bar: 6;. such.:clamp being provided with extensions I6 and I! fitting in ways in upper frame 8. A presser'foot18 on the lower end of clamp I5 is adapted to'enga'ge' a stack of sheets I9 upon table 2. The front face of the clamp is relieved, except for a region adjacent such foot and except for a bearing surface described below. The knife] andknife bar-6 :are thus slightlyspaced from the-front face ofthe binder clamp except along the foot of the latter. The clamp may be provided with a plurality of rearwardly extending resilient fingers which bear'upon .the upper surface of the stack.

Binder-clamp I5 is carried by a vertically extending screw 2| threadedly engaging nut 22 whlch'is lo'cked against rotation about avertical axis in such clamp and has any lateral play taken up. by means of set screw23; A collar 24 carried by spindle 25- constituting an upper extension of screw 2| is adapted'to engage 'the upper surface of bearing 26 ito-limit downw'ard movement of such spindle, and a'lower collar 21 similarly limitsup ward movement 101" the spindle. Upon driving shaft and screw 2| by means of gearing .28, 29 (see Rupp application Serial No. 123,865 above re ferred to), the binder'clamp will'be caused to travel upwardly or downwardly depending upon the 'directionof rotation'of such screw. Gearing 28, 29 may desirably be driven by means of an electric motor 30 carried by upper housingB.

An electric light such as fluorescent tube 3I may desirably be provided withinforwardly extending shield 32 to illuminate the upper surface of'stack I9 in the region engaged by the binder clamp presser foot.

While as above indicated the front face of binder clamp I 5 is for the most part relieved except adjacent thelower edge thereof, a'verti'ca'lly extending bearing surface 33 of substantial width i also provided adjacent the central portion-of the front face of such clamp. Such surface is fiat and lies in the same plane as the narrow unrelieved base-portion 34. As best shownin Fig; l, the front portion of surface 33 is offset to the'right; such surface being shaped and proportioned'toinsure that a limited co-acting bearing surface on-the knife bar will continue to engage the'same throughout the downward stroke of the latter," such knife bar ordinarily being slightly shifted longitudinally from right to left during the making of thecut to afford a slicing action.

Knife bari is drilledand tapped at 35 communicating with a slightly larger diameter opening in the rear face of the knife bar adapted to receive-the'head 3B of a screw 31 inserted therein (see-Fig, 5). The head of the screwis dimen stoned to bereceived entirely within such larger diameter ::opening in the knife bar'but'1may.1'pro-' tmde-=therefrom upon adjustment 0f the iserew;

rigidly support the former against any tendency toward rearward bowing of its center portion. The stack of sheets is next properly positioned upon table-2 and presser foot I8 brought down irito 'clanipmgwengagement therewith. This is accomplished by"r'ocking hand lever [3 to the right as shown in 1 to operate micro-switch 39, thereby completing a circuit energizing electricimotor 30 to drive spindle 25. When the stack has been thus clamped, the operator may now move the :hand leverto the left to engage the clutch. of the knife drive mechanism and I disengage the brake; drivingv crankshaft I2-=to reciprocate connectingrod I8 'and thereby reciprocate knifebar B and knife-1 to make-thecut, Upon completion of this cycle," lever=l 3 is automatically rocked in a clockwise direction back into sta'rting position-as shown in Fig. 1- and the knife drive clutch disengaged and the brake reapplied. When the binder clamp has been returned to-its fully elevated .positiomit will engage-limitswitfli 40', stopping motor 30. As above indicated the mechanism for thus reciprocating the clamp and knifeforms no-patt bf-theipresent in vention.

'When'knife I entersits but; the revere! th'eknife tends'to-ueneet tne-knife-and xiii-rem rearwardly in theircentraliportionsi thueslightly bowing the- 'same and iii' aii inabm cut; Engagement of properly adjusted screw head 36 with bearlh'gisiirface 33} however; efiectivelytoprevent any"such action, and "a' r'e markably accurate cut -isinstead; achieved:

The bevel of the-knife'edge is;-of course, always on' the-side' away from the binder'clamp and therefore ai aystendstc cause'bowing ofthe knife and knife bar toward such clamp. flection is particularlyap arent when-a' very wide stack is being cut. By meansof myad justing screw'Iam'enabled ensure an accurate cut despite" variations immaterial, wear or the bearing surfaces, and possible'initial lecseness of themounting of the binder clampi'in its ways. The transverserigidity 'of the binder clam'p thus utilized toprovide lateraisupport to the knife bar on the sidewhere needed, durihgleciprocation of suchba'r.

Other modes of applying the principle of the invention may. beemployed, change being niade as regards the details describedpprovided 1 the features statedin any of thefollowing claims or the equivalent of such be'employeds I-therefore particularly point out anddistinctly claimas my invention:

1. In=a paper 'cuttingi'-maehine "havingra table adapted to support "a stack of'sheets "thereon;- a vertically reciprocableclamp: adapted to clamp such'stack 'on such-tablei'and axknife 'adapted to be brought down adjacent such clamp-ta ent such stack; a knife supporting 'such -knife and secured thereto;- such'kmfe hayinga cutting edge 'beveled on the side "away ream siichblam'p whereby a tendency to transverse 'diictlonaiiss during' makihg of a -ci:lt,-' a flat vertical bearing surface on the sms of T such-cramp disposedadjacent and parallel to said knife bar and such knife, said bar-having an opening therethrough opposed to said surface, a flat-headed screw threadedly engaged in such opening with such head opposedto and adapted to be brought into engagement .with said surface, and a set screw adapted to lock said flat-headed screw in adjusted position, said surface being dimensioned to engage said fiat-headed screw during the cutting stroke of such knife to reinforce the latter edge beveled on the side away from such clamp whereby a tendency to transverse deflection arises during-making of a cut, such clamp having a face toward said bar and such knife relieved except for a narrow band along the foot thereof and a region" adjacent the central portion of such facei such region comprising a flat hearing surface lying in the same plane with such band parallel to such knife and said bar, said bar having an opening therethrough opposite such flat surface'on such clamp, a flat-ended screw threadedly-engaged in such opening with such end opposed to and adapted firmly to engage such iiatisurface', and means operative to lock said screw'in adjusted position, such flat surface being'iiimensioned to engage said flatended screwi'durihg the cutting stroke for such knife to reinforcefthe latter and said bar against deflection.

3. In a paper cutting machine having a table adapted to support a stack of sheets thereon, a vertically reciprocable clamp adapted to clamp such stack on such table, such clamp being transversely rigid and a knife adapted to be brought down adjacent such clamp'to out such stack; a knife bar supporting such knife and secured thereto, such knife having a cutting edge beveled on the side from such clamp whereby a tendency to transverse deflection arises during making'of a out, such clamp having a flat vertical bearing surface disposed toward and parallel to said knife bar and knife, a member carried by the central portion of said knife bar for adjustment relative to said bar toward and away from such adjacent clamp and adapted to be brought into engagement with a small portion of such" flat vertical surface on such clamp, and means operative to lock said member in adjusted position rigid with said bar, such flat surface 'being dimensioned slidingly to engage such member during the cutting stroke of such knife to reinforce the latter and said bar against deflection.

4. In paper cutting machines and the like having a table adapted to support a stack of sheets thereon, a vertically reciprocable transversely rigid clamp adapted to clamp such stack on such table, and a separately actuated knife adapted to be brought down adjacent such clamp to cut such stack; a knife bar supporting such knife and secured thereto, such knife having a cutting edge beveled on the side away from such clamp whereby a tendency to transverse deflection arises during making of a cut, and a member interposed between the opposed sides of said clamp and knife bar in a local region generally midway between the ends of the same, said member being mounted for adjustment forcibly to urge said clamp and bar apart in such local region during. making of the cut. 7

EREDERICK D. McLAUGI-ILIN.

REFERENCES CITED The followu'ng references are of record in the file of this patent:

McLauthlin Dec. 1, 1925 

